Nitrogen metabolism in young plants of African mahogany submitted to different concentrations of cadmium

The present study aimed to evaluate the biochemical changes in nitrogen metabolism promoted by the toxic action of cadmium (Cd) in young African mahogany plants (Khaya grandifoliola). The concentrations of cadmium were applied in the form of cadmium chloride monohydrate (CdCl2.H2O), using a completely randomized design (DIC), with five concentrations of CdCl2.H2O (0, 10, 20, 30 and 40 mg L-1) and seven replicates for each treatment. Analyzing the higher dosage of CdCl2.H2O in the present study, it was verified that the accumulation of cadmium in leaves and roots were equivalent to 228.5% and 743.75%, respectively, followed by reductions in the activity of the nitrate reductase enzyme. For the nitrate concentration, it was verified that the highest contents occurred in the leaves, reducing in the roots, the ammonium on the other hand, presented reduced contents in the foliar tissues. Already for the amino acids there was increase in the leaves. However, it can be inferred that young African mahogany plants (Khaya grandifoliola) it presented possible defense mechanisms that were able to prolong its biochemical activities.